Pipe-crawling autonomous robot designed to decommission nuclear plants

David Kohanbash, senior research programmer at the Carnegie Mellon University Robotics Institute, prepares the RadPiper robot for a test in a mockup pipe. Photo courtesy of
Carnegie Mellon University.

Carnegie Mellon University’s Robotics Institute have design a pair of autonomous robots that will be used to help decommission DOE nuclear facility in Piketon, Ohio.

The CMU robot will drive through miles of pipes at the former uranium enrichment plant to identify uranium deposits on pipe walls.

Unlike external measuring techniques, the autonomous robot is able to go inside the pipes to more accurately measure radiation levels.

“This will transform the way measurements of uranium deposits are made from now on,” predicted William “Red” Whittaker, robotics professor and director of the Field Robotics Center.

In May, the CMU team, led by Whittaker, will deliver the production prototypes, called RadPiper, to DOE’s 3,778-acre Portsmouth site.

The tetherless robot can move through the pipe at a steady pace atop a pair of flexible tracks. RadPiper is equipped with a lidar and a fisheye camera to detect obstructions ahead. After completing a run of pipe, the robot automatically returns to its launch point. Integrated data analysis and report generation frees nuclear analysts from time-consuming calculations and makes reports available the same day.

RadPiper treaded robot moves within the pipes of uranium-enrichment facilities to determine areas where radiation levels may pose a hazard. Photo courtesy of Carnegie Mellon University.

RadPiper was designed with a new “disc-collimated” radiation sensor, which uses a standard sodium iodide sensor to count gamma rays. The sensor is positioned between two large lead discs. The lead discs block gamma rays from uranium deposits that lie beyond the one-foot section of pipe that is being characterized at any given time.

The team worked closely with DOE and Fluor-BWXT Portsmouth, the decommissioning contractor, to build a prototype on a tight schedule and test it at Portsmouth last fall.

DOE officials estimate the robots could save tens of millions of dollars in completing the characterization of uranium deposits at the Portsmouth Gaseous Diffusion Plant in Piketon, and save perhaps $50 million at a similar uranium enrichment plant in Paducah, Kentucky.

RadPiper will operate in pipes measuring 30 to 42 inches in diameter and will characterize radiation levels in each foot-long segment of pipe. Those segments with potentially hazardous amounts of uranium-235 will be removed and decontaminated. The vast majority of the plant’s piping will remain in place and will be demolished safely along with the rest of the facility.

DOE has paid CMU $1.4 million to develop the robots as part of what CMU calls the Pipe Crawling Activity Measurement System. In addition to the Portsmouth and Paducah plants, robots could be useful elsewhere in DOE’s defense nuclear cleanup program.

www.cmu.edu